Recording medium, recording-medium management method, and recording-medium management system

ABSTRACT

A recording-medium management system comprising: a reproduction part; a recording part; and a control part. The control part performs a first through fourth control. The first control is to obtain a first data line from an authentication region of a recording medium by making the reproduction part read the authentication region, the authentication region including a first data pattern of a RAM bit and a ROM bit, the first data line being corresponding to the first data pattern, the RAM bit being over-writable of data at least once by a first writing condition, and the ROM bit being not over-writable of data by the first writing condition. The second control is to make the recording part overwrite predetermined data to the RAM bit. The third control is to obtain a second data line from the recording-medium, the second data line being corresponding to a second data pattern of the over-written RAM bit and the ROM bit. The fourth control is to perform an authentication with regard to the recording medium in reference to the first and second data lines.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2002-190264, filed onJun. 28, 2002; the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a recording medium, arecording-medium management method and a recording-medium managementsystem, and more particularly, it relates to a recording medium formanaging decryption of contents which are stored in the recordingmedium, propriety of access, etc., to the recording-medium managementmethod of performing authentication about this recording medium, and tothe recording-medium management system that performs authentication etc.about the recording medium.

[0003] The technology of copy protection for protecting copyrights of amusic software, video software, and application software, is becomingimportant with the spread of digitized data.

[0004] Particularly, a DVD (Digital Versatile Disc) video disc or aDVD-ROM disc etc. which adopts the digital recording system can beaccompanied as representative examples of the software for which a copyprotection is required. Encryption technology has been conventionallyused for the copy protection to the video software of these digitalrecordings.

[0005] The copy protection method using encryption technology performseffectively about the DVD video disc or DVD-ROM disc with which thealready encrypted data is recorded. However, in the case of DVD-RAM withwhich a user can record a new data, the following problems will arise.

[0006] (1) Management of the “encryption key” needed when encrypting isdifficult.

[0007] (2) Since a powerful encryption is difficult for the datarecording reproducing equipment (for example, DVD-RAM recorder which canperform recording and playback in digital like the analog videocartridge recorder which has spread widely) which is provided over auser's hand, a code is easy to be broken.

[0008] (3) In the case of a data recording reproducing equipment whichcan perform encryption and its decryption within the equipment, if thedata is again encrypted with the original data recording playbackequipment after decrypting the data which the user once created andencrypted with another data recording playback equipment, the contentsof data to be protected against a copy can be copied easily.

[0009] Because of these problems, it is difficult to operate the copyprotection using the conventional encryption technology effectivelyabout the record playback equipment of digital video data.

[0010] Moreover, if an original copy protection processing is performedfor a data recording medium for DVD-RAM by the DVD-RAM drive system,there will be a problem that a copy protection processing circuitbecomes complicated when reproducing the medium with a DVD-ROM drive orreproducing a DVD-ROM disc with the DVD-RAM drive

[0011] This also becomes the factor which increases the product cost ofthe DVD-RAM drive.

SUMMARY OF THE INVENTION

[0012] According to an embodiment of the invention, there is provided arecording medium comprising: an authentication region having a RAM bitand a ROM bit, the RAM bit being over-writable of data at least once bya first writing condition, and the ROM bit being not over-writable ofdata by the first condition; and a data storing region.

[0013] According to other embodiment of the invention, there is provideda recording-medium management method comprising: obtaining a first dataline from an authentication region of a recording medium, theauthentication region including a first data pattern of a RAM bit and aROM bit, the first data line being corresponding to the first datapattern, the RAM bit being over-writable of data at least once by afirst writing condition, and the ROM bit being not over-writable of databy the first writing condition; overwriting predetermined data to theRAM bit; obtaining a second data line from the recording medium, thesecond data line being corresponding to a second data pattern of theover-written RAM bit and the ROM bit, and decrypting an encrypted datastored in a data storing region of the recording medium in reference tothe first and second data lines.

[0014] According to other embodiment of the invention, there is provideda recording-medium management method comprising: obtaining a first dataline from an authentication region of a recording medium, theauthentication region including a first data pattern of a RAM bit and aROM bit, the first data line being corresponding to the first datapattern, the RAM bit being over-writable of data at least once by afirst writing condition, and the ROM bit being not over-writable of databy the first writing condition; overwriting predetermined data to theRAM bit; obtaining a second data line from the recording medium, thesecond data line being corresponding to a second data pattern of theover-written RAM bit and the ROM bit, and judging propriety of an accessto a data storing region of the recording-medium in reference to thefirst and second data lines.

[0015] According to other embodiment of the invention, there is provideda recording-medium management system comprising: a reproduction part; arecording part; and a control part performing a first control to obtaina first data line from an authentication region of a recording medium bymaking the reproduction part read the authentication region, theauthentication region including a first data pattern of a RAM bit and aROM bit, the first data line being corresponding to the first datapattern, the RAM bit being over-writable of data at least once by afirst writing condition, and the ROM bit being not over-writable of databy the first writing condition; a second control to make the recordingpart overwrite predetermined data to the RAM bit; a third control toobtain a second data line from the recording-medium, the second dataline being corresponding to a second data pattern of the over-writtenRAM bit and the ROM bit, and a fourth control to perform anauthentication with regard to the recording medium in reference to thefirst and second data lines.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be understood more fully from thedetailed description given herebelow and from the accompanying drawingsof the embodiments of the invention. However, the drawings are notintended to imply limitation of the invention to a specific embodiment,but are for explanation and understanding only.

[0017] In the drawings:

[0018]FIGS. 1A and 1B are schematic diagrams showing an example of therecording medium according to the embodiment of the invention;

[0019]FIG. 2 is a schematic diagram showing the recording-mediummanagement system concerning the embodiment of the invention;

[0020]FIGS. 3A through 3C are schematic diagrams explaining theauthentication method performed by a recording-medium management system;

[0021]FIGS. 4A through 4C are schematic diagrams showing the differencebetween the original medium and the copied medium mentioned above;

[0022]FIGS. 5A through 5C are schematic diagrams which illustrate theauthentication process in a system like HDD;

[0023]FIG. 6 is a schematic diagram which illustrates the recordingmedium which has two or more authentication regions;

[0024]FIG. 7 is a schematic diagram showing the example of applicationof restoration processing;

[0025]FIGS. 8A through 8F are process sectional views showing themanufacturing method of the recording medium in this example;

[0026]FIG. 9A is a schematic diagram showing the result of havingobserved the surface of the sample by the evanescent light microscope;

[0027]FIG. 9B is a schematic diagram showing the result of havingobserved the surface of the sample by the evanescent light microscope;

[0028]FIG. 10 is a sectional view showing a recording medium and thehead slider of optical record playback equipment;

[0029]FIG. 11 is a diagram showing the plane structure of minuteopenings provided in the head slider;

[0030]FIGS. 12A through 12D are process sectional views showing theprincipal part of the manufacturing method of the recording medium inthe example;

[0031]FIG. 13 is a schematic diagram showing the result of havingobserved the surface of the sample using MFM (Magnetic ForceMicroscope):

[0032]FIG. 14 is a sectional view showing the recording medium and thehead slider of magnetic record playback equipment of this example;

[0033]FIG. 15 is an outline figure showing the plane structure of thehead slider 70;

[0034]FIG. 16 is a schematic diagram showing the recording medium ofthis example;

[0035]FIG. 17 is a schematic diagram which illustrates a card-likerecording medium;

[0036]FIG. 18 is a schematic diagram showing the recording-mediummanagement system which manages the recording medium of the shape ofsuch a card;

[0037]FIG. 19 is a schematic diagram showing the recording medium whichused semiconductor memory and a magnetic material memory; and

[0038]FIG. 20 is a schematic diagram showing the recording-mediummanagement system which manages the recording medium which expressed inFIG. 19.

DETAILED DESCRIPTION

[0039] Hereafter, some embodiment of the invention will be explained,referring to drawings.

FIRST EXAMPLE

[0040] First, an example of the recording medium and an authenticationmethod using the recording medium according to the embodiment of theinvention will be explained.

[0041]FIGS. 1A and 1B are schematic diagrams showing an example of therecording medium according to the embodiment of the invention.

[0042] That is, the disc-like recording medium is expressed in FIG. 1A.This disc is, for example, a recording medium using either of variouskinds of recording modes, such as a hard disc, other magnetic discs,optical discs such as DVD and CD, and magneto-optical discs including MO(Magneto-optical) discs.

[0043] However, the form of the recording medium of the invention is notlimited in the shape of a disc, but it can be used in various kinds offorms, such as the shape of a card, the shape of a tape, and the shapeof a film, which will be explained in detail after. Furthermore, it isalso possible to apply the invention to the recording medium providedwith the so-called semiconductor memory.

[0044] Now, as expressed in FIG. 1A, the authentication region 20 isprovided in recording medium 10A of the embodiment. Although the examplein which one authentication region 20 is provided near the center of adisc-like medium is expressed in FIG. 1A, the position of theauthentication region 20, or its number can be determined appropriatelyaccording to a use, as explained in detail after.

[0045] In the recording medium 10A, region other than the authenticationregion 20 is the data storing region 30, which, for example, can be theso-called ROM (read only memory) region where data can only read.However, this data storing region 30 may be so-called RAM (random accessmemory) region where data can be written and read, so-called write onceregion (write once memory) where data can written only once, or a regionwhich combines any of the ROM region, the RAM region and the write onceregion.

[0046] And in one embodiment of the invention, the data stored in thisdata storing region 30 is encrypted as explained in detail after. Andthe “encryption key” for carrying out decryption of this encrypted datais stored in the authentication region 20.

[0047] Moreover, in another embodiment of the invention, a proprietyjudgment about various kinds of processes, such as access to the datastored in the data storing region 30, operation about this data,computation, and installation, is made based on the data stored in theauthentication region 20. That is, when the data acquired in theauthentication region 20 is not the predetermined contents, operation ofapplication software, installation, a copy, etc. are forbidden.

[0048]FIG. 1B is a partly enlarged view of the authentication region 20.The authentication region 20 of the invention has the RAM bits 24, theROM bits 26, and the non-recording region 22 that encloses thecircumference of these bits. The non-recording region 22 is a regionwhere a recording of information by the record playback head 200 is notperformed. Although it is desirable for this non-recording region to beconstituted by the material which cannot store information, it mayconsist of material which can store information.

[0049] And in this figure, the RAM bits 24 are the minimum units whichcan store information by the record playback head. That is, the RAM bits24 are bits to which information can be recorded or can be overwrittenby the record playback head etc.

[0050] Any materials which can store information by a certain techniquecan be used as material of the RAM bit 24. For example, the magneticbody which can store information magnetically, the phase change mediumwhere the reflectivity of a light changes with crystal-amorphous phasetransitions, various chromic materials where the color changes byelectric fields, optical irradiation, heating, and oxidation-reductionreaction, materials whose form change and materials whose electricconduction, permittivity or optical transmissivity change, can bementioned.

[0051] Furthermore, the material which can store information byaccumulating an electric charge, like a semiconductor RAM memory can beused. The method with which information can be rewritten repeatedlyusing a reversible recording mode like magnetic recording can be used asthe recording method to the RAM bits. Or the method with whichinformation can be written only once using the irreversible recordingmode of applying heat like a write once system can be used as therecording method to the RAM bits.

[0052] On the other hand, the ROM bits 26 are regions where informationcannot be overwritten, or a region where information cannot beoverwritten unless a different method from the RAM bit 24 is used.However, these ROM bits 26 are also bits whose information can be readby the record playback head etc, as well as the RAM bits 24. That is,the ROM bits 26 are regions which give “0” or “1”, or the sameinformation as the information on the last RAM bit or ROM bit.

[0053] The RAM bits 24 and the ROM bits 26 are arranged in theauthentication region 20 at a certain fixed interval according to thereading clock frequency of record playback equipment. However, theinterval can be appropriately determined according to the specificrecord reproduction system, and may not necessarily be a fixed interval.

[0054] And in the embodiment, at least one RAM bit 24 and one ROM bit 26are provided in one authentication region 20, respectively. The numberand the order of arrangement of these RAM bit 24 and the ROM bits 26 canbe appropriately determined according to use. Moreover, the arrangementmay not necessarily be the one dimensional arrangement as illustrated inFIG. 1B, but may be two dimensional along a predetermined plane, andalso in the case of a multilayer recording medium etc., the threedimensional arrangement is also possible.

[0055] However, as for the arrangement pattern of the RAM bits 24 andthe ROM bits 26 in the authentication region 20, it is desirable for itto be unable to predict.

[0056] That is, as for arrangement of the RAM bits and ROM bits in theauthentication region 20, it is desirable not to change the arrangementby whether the bit is a RAM bit or a ROM bit, but to be arranged under afixed rule for both of the bits. It is desirable that it is difficult todistinguish the ROM bit from the RAM bit only by accessing each bit inthe authentication region 20 with the playback head or a recording head.Furthermore, it is desirable to make the prediction difficult by usingtwo or more arrangement patterns at random for every disc.

[0057] For example, the arrangement pattern may be different for everyrecording medium. This is because the prediction of “key B” will becomedifficult and the reliability of a copy protection will become higher asexplained in full detail later.

[0058] Hereafter, the authentication process which can be performedusing such a recording medium will be explained.

[0059]FIG. 2 is a schematic diagram showing the recording-mediummanagement system concerning the embodiment of the invention.

[0060] That is, this management system has the record playback head 200which performs record and reproduction to a recording medium 10, and thecontrol part 300 which performs read-out of data, writing, and dataprocessing through this head 200 This management system may be playbackequipment for reproducing the data stored in the data storing region 30of a recording medium 10, or may be recording equipment which writesdata in the data storing region 30.

[0061]FIGS. 3A through 3C are schematic diagrams explaining theauthentication method performed by a recording-medium management system.

[0062] That is, the processes of the authentication method of theinvention includes the steps of “getting key A”, an “overwrite erase”,and “getting key B”.

[0063] In the system shown in FIG. 2, these processes are performed,when the control part 300 operates the head 200 appropriately. Theprocess of these three steps may be performed in the first through thirdcontrol parts 300A, 300B, and 300C of the control part 300,respectively, as shown in FIG. 2.

[0064] Or the process of these three steps may be performed using thesame region in the control part 300.

[0065] In this example, the case where it is possible for all the ROMbits 26 to be read as specific bit information, such as “0” and “1”, bythe record playback head 200 is accompanied as an example.

[0066] The states of the authentication region 20 in each step areexpressed in FIG. 3A through FIG. 3C.

[0067] Here, the non-recording region 22 which encloses thecircumference of the RAM bits 24 and the ROM bits 26 is a region whereinformation cannot be recorded by the record playback head 200.

[0068] In FIGS. 3A through 3C, the white circle expresses for RAM bits24A in which “0” is written, and the black dot expresses RAM bits 24B inwhich “1” is written.

[0069] The information on these RAM bits 24A and 24B can be overwrittenwhen the record playback head 200 records information on these bitsagain.

[0070] In the authentication method of the embodiment, the informationfor getting “key A” is beforehand written in the authentication region20.

[0071]FIG. 3A expresses the process of getting the “key A” in theembodiment. That is, in the authentication region 20, the RAM bits 24(24A, 24B) in which “0” or “1” is written, and the ROM bits 26 arearranged. The record playback head 200 reads this region. In thisexample, it is supposed that the ROM bit 26 is read as “0.” However, theinvention is not limited to this example.

[0072] When the record playback head 200 reads the authentication region20 in FIG. 3A, RAM bits 24A expressed with a white dot and the ROM bits26 will be read as “0”, and RAM bit 24B expressed with the black dotwill be read with “1.” That is, this authentication region 20 is read as“00101001.” This is recognized as the “key A.”

[0073] Next, an “overwrite erase” is performed as expressed in FIG. 3B.That is, after getting the “key A”, the information “11111111” isoverwritten by a recording head 200 to this authentication region 20.

[0074] As a result of a recording head's trying to write the signalshowing “1” in all the bits in the authentication region 20 by this“overwrite erase” processing, all RAM bits 24A (white circle) showing“0” and RAM bits 24B (black dot) that expresses “1” in theauthentication region 20 are replaced by bits 24B (black dot) showing“1.” However, the information on the ROM bits 26 on this authenticationregion 20 does not change, and record of “0” is maintained in theexample of FIG. 3B.

[0075] Next, “key B” is got as expressed in FIG. 3C. That is, when aplayback head 200 reads the authentication region 20 again after the“overwrite erase” step, the bit data corresponding to “key B” areobtained.

[0076] Here, all RAM bits 24 in this authentication region 20 are bits24B (black dot) which expresses “1” after the above-mentioned “overwriteerase” process, and on the other hand, there is no change in the ROMbits 26 showing “0.” Therefore, the bit data “10111011” are read by theplayback head 200, and this is recognized as the “key B.”

[0077] The control part 300 expressed to FIG. 2 can generate the “key”used for encryption, decryption, or authentication, using both the “keyA” and the “key B” read by the above procedure. And decryptionprocessing of the code of the encrypted data which is recorded on thedata storing region 30, i.e., a decipherment, is performed, using thiskey.

[0078] The method of generating the key using “key A” and “key B” may bea method of connecting the key A and Key B in order and using as onekey, for example, and any other methods may be employed as well.

[0079] For example, only one encryption key may be generated from the“key A” and “key B.” Two or more keys may be generated by obtaining oneencryption key as “key C” by carrying out bit addition of “key A” andthe “key B” and by obtaining a “key D” by carrying out bit subtractionof “key A” and the “key B”.

[0080] The procedure of the encryption, decryption, and authenticationusing the key obtained from “key A” and “key B” of the invention is notlimited to any specific one. General encryption or a generalauthentication means is disclosed by D. W. Davies and W. L. Price“Security for Computer Networks second edition” JOHN WILEY & SONS,William Stallings “Cryptography and Network Security Principles andPractice Second Edition” Prentice Hall.

[0081] For example, the key obtained from Key A and Key B of theembodiment can be used for the DES (Data Encryption Standard) methodusing a secret key, and the RSA (Rivest, Shamir and Adleman) methodusing a public key.

[0082] Moreover, when doing authentication work, the key of theembodiment can be used as MAC (Message Authentication Code).

[0083] By using the recording medium and the authentication method ofthe embodiment which were explained above, a powerful copy protectionbecomes possible.

[0084] That is, in the embodiment, since the authentication region 20 isthe composition that the RAM bits 24 and the ROM bits 26 areintermingled as mentioned above, when the usual playback head 200accesses this region, it is difficult to distinguish which bit is theROM bit or the RAM bit in the authentication region 20.

[0085] Therefore, for example, when original recording medium 10A (forexample, DVD-ROM) before performing authentication processing in theinvention is copied to another copy recording medium (for example,DVD-RAM), the authentication region 20 is also copied together.

[0086] However, only the bit information stored in these RAM bits 24 andthe ROM bits 26 is copied at this time, and the bit arrangementinformation of the RAM bits 24 and the ROM bits 26 is not copied.

[0087] Therefore, in a recording medium with the authentication regionof the embodiment (original medium) and the recording medium which hasthe authentication region where arrangement of a RAM bit and a ROM bitdiffers from each other or which does not have the authentication regionof the embodiment (copied medium), a result of authentication processingi.e., the acquisition result of “key A” and “key B” differs. In thecopied recording medium in which all the data of an original medium arecopied, all the regions where the authentication regions are copied areconstituted by the RAM bit which can be overwritten.

[0088] If a process for getting “key A” is performed to this copiedauthentication region, the same key A as an original recording medium isacquirable.

[0089] However, following to this, if “overwrite erase” processing isperformed to the authentication region of this copied medium, since allthe bits in an authentication region in a copy medium are RAM bits, thepattern used for the overwrite erase will be recorded as it is.

[0090] Therefore, when “key B” is got next, since the pattern of an“overwrite erase” is written in as it is, as for the informationcurrently recorded on the authentication region on a copied recordingmedium, an overwrite erase pattern is read.

[0091] On the other hand, since the RAM bits and the ROM bits areintermingled as above-mentioned in the authentication region of anoriginal recording medium, also when an overwrite erase is performed, itcannot record on a ROM bit. Therefore, an overwrite erase pattern andthe pattern of Key B are different.

[0092] That is, since the “keys B” obtained differs with an originalrecording medium and a copied recording medium, the “key B” decipherablein an original recording medium cannot be obtained in a copied recordingmedium. Therefore, in the copied recording medium, decryption of thedata stored in the data storing region 30 cannot be performed, andcontents cannot be reproduced.

[0093]FIGS. 4A through 4C are schematic diagrams showing the differencebetween the original medium and the copied medium mentioned above.

[0094] In the figures, getting the “key” in the authentication region 20on an original medium is the same as the example expressed in FIGS. 3Athrough 3C. That is, “00101001” is obtained as “a key A”, “11111111” iswritten in an authentication region in an “overwrite erase”, and“10111011” is obtained as “a key B” in the original medium.

[0095] On the other hand, since “key A” is copied as it is in theauthentication region on the copied medium, the same “00101001” as anoriginal medium is obtained as “a key A” as expressed in FIG. 4A.

[0096] Next, when the “overwrite erase” by “11111111” patterns isperformed on the copied medium as expressed in FIG. 4B, since all bitsconsist of RAM bits, all the bits of an authentication region will beoverwritten by this pattern. Therefore, in the getting process of the“key B” following this, the bit pattern of an overwrite erase isacquired as “a key B” as it is on the copied medium, and “11111111” isobtained.

[0097] That is, in an original medium, since the ROM bits 26 areprovided, “key B” is set to “10111011” different from the pattern of anoverwrite erase. However, in the copied medium, it is the “11111111”which is same as an overwrite erase pattern, and the correct “key B” isnot obtained. Therefore, decryption of the encrypted data recorded onthe data storing region 30 becomes impossible in a copied medium.

[0098] In above-mentioned explanation, the example in which decryptionprocessing of the encrypted data stored in the data storing region 30 isperformed using “key A” and “key B” was given. But the invention is notlimited to this example.

[0099] For example, by using the “key A” and “key B”, the propriety ofreproduction operation of the contents stored in the data storing region30 may be determined, and propriety of installation of applicationsoftware and the execution operation which are stored in the datastoring region 30 may be determined.

[0100] In these cases, the data corresponding to “key A” and “key B” arestored also in the data storing region 30. And only when the “key A” and“key B” obtained in the authentication region 20, and thesecorrespondence data stored in the data storing region 30 agree,reproduction of the contents stored in the data storing region 30,execution of application software or installation, etc. can bepermitted.

SECOND EXAMPLE

[0101] Next, an example in which the ROM bit 26 is read as the same bitdata as the data of the bit in the immediately preceding of that in theauthentication region 20 will be explained.

[0102] The pattern of the “overwrite erase” in the embodiment does notneed to be the continuation of the same bit data like “0000 . . . ” and“11111 . . . ” as shown in the first example, but may be set by thesignal characteristic acquired from the ROM bits 26 in the recordreproduction system using the invention.

[0103] For example, when using the optical recording medium such as CD,DVD, etc., the intensity of the reflected light from each bit isrecognized as a bit signal respectively in many cases. That is, themethod of reading of treating it as the signal of “1” if it is more thana threshold with intensity, and treating it as the signal of “0” ifsmaller than a threshold is used. Thus, when recognizing the informationfrom each bit by a fixed threshold, it is effective to make an overwriteerase signal continuation of the same bit signals, such as “0000 . . . ”and “1111 . . . ” described before.

[0104] On the other hand, in the case of HDD (Hard Disc Drive) etc., theROM bits on a magnetic information recording medium may be regionswithout magnetic information. In this case, the signal from such ROMbits is recognized to be the same signal as the signal from the bit readimmediately before on the characteristic of magnetic reading heads, suchas a GMR (giant magneto-resistance effect) head.

[0105] For example, in an authentication region, if the immediatelypreceding bit of a ROM bit is “0”, the ROM bit will also be recognizedto be “0.”

[0106] In this case, as a pattern used for an “overwrite erase”, thepattern in which the same signal continued as shown in “1111 . . . ” ofa precedent is not desirable. Because, when the overwrite erase of theauthentication region where the RAM bits and ROM bits in the embodimentare intermingled is carried out by the continuation pattern of thesignal same like “111 . . . ”, since “1” is recorded as for all RAMbits, and the same signal as the last bit is recognized to a ROM bit,wherever the ROM bit may be in an authentication region “1111 . . . ”equal to an overwrite erase pattern will be obtained as “key B”.

[0107] Thus, as for the pattern used for an overwrite erase, in the caseof a system which recognizes a ROM bit to be the same data as the bitread just before, it is desirable to make it the bit-data sequence inwhich different bit data appears by turns like “010101 . . . ”.

[0108]FIGS. 5A through 5C are schematic diagrams which illustrate theauthentication process in a system like HDD.

[0109] In FIG. 5A, when acquiring “key A”, the ROM bits 26 of theauthentication region 20, i.e., the 3rd and the 6th record bits from theleft in the figure, are read as equal to the bits in front of that. Thatis, “0111000” is obtained as “key A.”

[0110] Next, as expressed in FIG. 5B, an overwrite erase is performedusing the bit pattern arranged “1010101”, “1”, and “0” by turns.

[0111] Then, in the case of read-out of “key B”, as expressed in FIG.5C, since it supposes that the ROM bits 26 are equal to the immediatelypreceding bit, “1000111” is obtained as “a key B.”

[0112] Thus, since “key B” serves as different bit data from anoverwrite erase pattern “1010101”, if this overwrite pattern is used, itcan be distinguished from the “key B” generated by the recognitionregion copied on the copied medium, and will become effective as a copyprotection.

[0113] Thus, as for the overwrite pattern used when an “overwriteerase”, it is desirable to be appropriately determined according to thecharacteristic of the system how the RAM bits 24 and the ROM bits 26 areread. That is, it is chosen appropriately whether an overwrite patternis made continuation of the same bit data, or it is made a differentcombination of bit data. In addition, in this example, “11111111” and“1010101” were used as an overwrite pattern. However, the invention isnot limited to this, but if it becomes the bit data with which anoverwrite pattern differs from “key B”, any overwrite patterns can beused.

THIRD EXAMPLE

[0114] Next, the example using the recording medium which has two ormore authentication regions as the third example of the invention willbe explained.

[0115] That is, by the authentication method of the invention, afterperforming the overwrite erase contained in the process of theauthentication method, it becomes impossible to investigate what kind ofinformation of key A was written before the overwrite erase to the RAMbits on the recording medium. Therefore, in the embodiment, when thesame authentication region is used, it is impossible to carry outauthentication repeatedly without “restoration processing” mentionedlater.

[0116] That is, the embodiment has the feature that the authenticationprocedure using one authentication region is possible only for once,without carrying out “restoration processing.”

[0117] If this feature is used, it will become possible to restrict thenumber of times of reference of the contents recorded on the recordingmedium.

[0118] For example, suppose that one movie contents are recorded on thedata storing region 30 of recording-medium 10A, and these movie contentsare encrypted. And, suppose that the encryption key is generated using“key A” and “key B”, and the “key A” and “key B” are recorded on theauthentication region 20.

[0119] When reproducing the movie contents of this recording medium 10A,a series of process of getting “key A”, an “overwrite erase”, and “keyB” is carried out to the authentication region 20 according to theprocedure mentioned above. And, “key A” and “key B” are acquired, anencryption key is obtained from these, contents are decrypted, andaccess and reproduction to contents are attained.

[0120] However, if the authentication procedure is preformed again,acquisition of “key A” becomes impossible because “overwrite erase” hasalready been performed.

[0121] Therefore, it becomes impossible to carry out authentication workonce again and to access contents to the medium for which contents havebeen accessed once. That is, the feature that contents can be accessedonly once is realizable.

[0122] Using this feature that an authentication process can beperformed only once until one authentication region performsreproduction processing mentioned later, if two or more authenticationregions are made to correspond to one contents the access restrictionfunction in which contents can be accessed to only the number of timesof the number of that authentication region can be offered.

[0123]FIG. 6 is a schematic diagram which illustrates the recordingmedium which has two or more authentication regions. That is,recording-medium 10B of this example has four authentication regions20A-20D.

[0124] For example, if an encrypted movie contents are stored in thedata storing region 30 of this recording medium and “key A” and “key B”are stored in the authentication regions 20A-20D respectively, it willbecome possible to carry out the authentication work four times, thatis, to reproduce movie contents four times.

[0125] In this case, the four “keys A” and “keys B” which are stored inthe authentication regions may be completely the same or are differentfrom each other among four authentication regions 20A-20D. In otherwords, the arrangement pattern of the RAM bits and ROM bits in eachauthentication region, and the signal prerecorded on the RAM bits may becompletely same or may be different for each authentication region. Thatis, “key A” and “key B” may be changed for every authentication region,or may be same for every authentication region.

[0126] And, for example, if one contents are divided into two or morechapters and either of the authentication regions 20A-20D is assigned toeach chapter, it becomes possible to access each of chapter after a setperiod of time without accessing the whole contents at once.

[0127] In addition, in the embodiment, also about the number or thearrangement of the authentication regions established in a recordingmedium, it is not limited to the example shown in FIG. 6, but can beappropriately determined according to a use.

FOURTH EXAMPLE

[0128] Next, “restoration processing” which returns an authenticationregion to the state before an overwrite erase will be explained as thefourth example of the invention.

[0129] In the recording medium of the embodiment, the authenticationregion after the authentication process is performed is considered to bethe state where the overwrite erase is carried out, as mentioned aboveabout FIGS. 3A through 5C. Therefore, an authentication process isunrepeatable once again with this state.

[0130] Then, if the data of “key A” is written in an authenticationregion once again, an authentication process can be performed again.Such a process of the writing “key A” will be called “restorationprocessing.” This restoration processing can be performed using arecording-medium management system which expressed in FIG. 2.

[0131] When the position of the authentication region on a recordingmedium is known (for example, when a track, a sector, etc. on which anauthentication region is arranged are decided), it is possible toperform restoration processing by simple write-in processing.

[0132] On the other hand, when the position of an authentication regionis not known on a recording medium, it is necessary to look for anauthentication region on a medium by making arrangement of the RAM bit24 and the ROM bit 26 the clue. Therefore, in this case, the recordsystem with which RAM bits and ROM bits can be distinguished andidentified on a recording medium, a recognition region can be judgedafter an appropriate time, and the predetermined “key A” can be writtenis needed.

[0133]FIG. 7 is a schematic diagram showing the example of applicationof restoration processing. That is, this figure expresses therestoration processing in a video rental shop 500.

[0134] A video rental shop 500 has the recording medium 10 with theauthentication region of the invention, and restoration equipment S1which can restore this authentication region.

[0135] On the other hand, a user 600 has playback equipment S2 which cancarry out the authentication work of the invention.

[0136] In a video rental shop 500, the record media 10 which had theauthentication region restored by restoration equipment S1 are lent to auser 600.

[0137] A user 600 needs to carry out authentication work in order toaccess the encrypted contents, when perusing the lent record media 10with the playback equipment S2 which the user owns. And a user 600carries out authentication work, obtains an encryption key from “key A”and “key B”, and accesses contents.

[0138] Since the overwrite erase of the authentication region used forthe authentication work is carried out once the authentication work isperformed, it becomes impossible to do authentication work again as itis.

[0139] Since the key which the playback equipment S2 which a user 600owns read at the time of authentication can decrypt the datacorresponding to the authentication region any number of times as far asthe playback equipment S2 has memorized the key, it is disadvantage tothe realization of prohibition of two or more authentication in theinvention. Therefore, it is desirable to have the system whicheliminates the memory which saved the “key A” and “key B” read in theauthentication region in a user's playback equipment S2 in theinvention.

[0140] As for delete of memory of this the “key A” and “key B”, it isdesirable to be carried out when a certain fixed phenomenon occurs. Themoment when playback equipment S2 deletes “key A” and “key B” may be,for example, the moment when reading of all data from the recordingmedium 10 equipped with the authentication region is finished, themoment when its recording medium is picked out from playback equipmentS2, the moment of when using playback equipment S2 is finished, or themoment of when the a stop switch and a power supply off-switch arepushed. However, the moments when playback equipment S2 deletes “key A”and “key B” are not limited to the above-mentioned moments.

[0141] The user 600 returns the recording medium 10 to the video rentalshop 500 after referencing contents. In the video rental shop 500, auser can be again provided with the recording medium 10 in the state inwhich authentication work can be carried out again by returning theauthentication region of the returned recording medium 10 to the statein which “key A” can be acquired again with restoration equipment S1.

THE FIFTH EXAMPLE

[0142] Next, an example will be given and explained about thefabrication method of the recording medium of the invention as the fifthexample of the invention.

[0143] The authentication region in the invention is a region where theRAM bits 24 and the ROM bits 26 are intermingled. As a method ofcreating this region, firstly the method of creating RAM bitsarrangement at the predetermined intervals on the recording medium,secondly changing a specific RAM bit into the ROM bit which cannot bewritten in by carrying out destruction or property modification can bementioned. By this technique, since the authentication region of amedium is drawn directly, a different authentication region for everymedium can be created, unlike the sixth example mentioned later.

[0144] Hereafter, the manufacturing method of the recording medium ofthis example will be explained, referring to drawings.

[0145]FIGS. 8A through 8F are process sectional views showing themanufacturing method of the recording medium in this example.

[0146] First, as shown in FIG. 8A, nickel is plated to originalrecording medium 102 and the stamper 104 is formed. That is, an electronbeam resist is applied on the silicon substrate of larger size thanmedium size, and the openings of the resist are formed in the bitpositions of the medium by electron beam drawing.

[0147] Then, RIE (Reactive Ion Etching) processing is performed and theoriginal recording medium 102 having concave dot patterns 102D iscreated. Electroforming processing of nickel is performed to thisoriginal recording medium 102, and the stamper 104 made from nickel isformed. The nickel stamper 104 has convex parts 104P corresponding tothe bit positions of a medium.

[0148] Next, as shown in FIG. 8B, the Pt reflective film 108 with athickness of about 30 nm on the glass substrate 106, A1203 film 110 witha thickness of about 50 nm to be a matrix, and the resist film 112 witha thickness of about 50 nm are formed. And the resist 112 surface wasprocessed using nano-imprint lithography by pressing the stamper 104against the surface of the resist film 112, and recesses 112Dcorresponding to the bit position of a medium are formed. Next, as shownin FIG. 8C, the resist film 112 is etched by RIE and the surface form ofa resist 112 is transferred on the matrix film 110. That is, recess 110Dcorresponding to the bit position of a medium is transferred by thesurface of the matrix film 110.

[0149] Next, as shown in FIG. 8D, the RAM bits 24 are formed and theplanarizing of the surface is carried out. That is, the RAM bits 24 areformed by forming phase change material In—Sb—Te with a thickness ofabout 30 nm as a film and embedding at the holes.

[0150] Then, the surface is ground by CMP (chemical mechanicalpolishing), and carried out the planarizing.

[0151]FIG. 9A is a schematic diagram showing the result of havingobserved the surface of the sample which is formed in this way by theevanescent light microscope. As shown in FIG. 9A, the RAM bits 24 arelocated in a line at equal intervals in A1203 matrix 110.

[0152] Then, ROM bits are formed by making parts of RAM bits into ROMbits following formation of the above aggregates of the RAM bits 24.That is, as shown in FIG. 8E, the ROM bits 26 are formed by removingspecific RAM bits. On the obtained recording medium, the portion inwhich the eight RAM bits 24 of a predetermined region arranged on atrack is considered to be the authentication region 20, and In—Sb—Te ofthe predetermined RAM bits 24 of this portion are heated by the electronbeam heating, and removed. And the protective film 114 is formed on it.

[0153] Alternatively, as shown in FIG. 8F, a different material may beembedded into the portions where the RAM bits are removed in order tomake ROM bits 26. For example, a protective film 114 or any othermaterial may be embedded into the portion where the RAM bits 24 areremoved.

[0154]FIG. 9B is a schematic diagram showing the result of havingobserved the surface of the sample formed in this way by the evanescentlight microscope. The record region 30 and the authentication region 20where the RAM bits 24 and ROM bits 26 aligned are observed in the matrix110.

[0155] The first bit, the second bit, the fourth bit, the fifth bit, theseventh bit, and the eighth bit of the authentication region 20, are thesame RAM bits 24 as the RAM bit 24 of a record region. Third bit and thesixth bit of the authentication region 20 are the ROM bits 26 formed byremoving the phase change material.

[0156]FIGS. 10 and 11 are schematic diagrams showing the principal partof the recording-medium management system as phase change light recordplayback equipment which can reproduce the recording medium of thisexample.

[0157] That is, FIG. 10 is a sectional view showing a recording mediumand the head slider of optical record playback equipment. The recordingmedium 141 of this example has the recording layer which has the recordtrack belt in which the RAM bits 24 carried out rule arrangement on theglass substrate 106, and the protection layer 114.

[0158] This recording medium 141 is equipped with the spindle motor 142,and rotates with the control signal from the control part which is notillustrated. The optical laser resonance type detection read-out head144 and the field oscillation type laser write-in head 145 are providedat the tip of the head slider 143.

[0159] The position of the head slider 143 is determined by the two-stepactuator which is not shown.

[0160]FIG. 11 is a diagram showing the plane structure of minuteopenings provided in the head slider. Here, the size of the length ofthe minute opening of the read-out head 144 is about 35 nm, and the sizeof width of that is about 20 nm. The size of the length of the minuteopening of the write-in head 145 is about 20 nm, and the size of widthof that is about 20 nm.

[0161] This recording playback equipment can perform seeking operation,acquisition of “key A”, an overwrite erase, acquisition of “key B”,record read-out about other record bits, tracking of a read-out head,and evasion operation of the writing to a defective region, to the RAMbits 24 and the ROM bits 26, of the patterned recording medium 141, andother record bits.

[0162] As a result of performing an authentication process using anoverwrite erase pattern “11111111” with the technique of the firstexample mentioned above to the recording medium of this example usingthis record playback equipment, “key A” and “key B” are acquired.

[0163] Moreover, by the copied medium formed by copying this recordingmedium to a RAM medium, it has checked that it could not reproduce.

THE SIXTH EXAMPLE

[0164] Next, an example is given and explained about another creationmethod of the recording medium of the invention as the sixth example ofthe invention.

[0165] That is, in this example, in the region in which the bit on arecording medium is not formed, the RAM bits 24 are created in specificarrangement into the specific portion, and the portion in which the RAMbits 24 are not formed is made into the ROM bits 26.

[0166] Specifically, the authentication region is drawn in the case ofthe original recording creation in the nano-imprint technique. By thistechnique, all of the stampers obtained from original recording mediumand the recording media obtained from these stampers have theauthentication region of the same pattern.

[0167]FIGS. 12A through 12D are process sectional views showing theprincipal part of the manufacturing method of the recording medium inthis example.

[0168] First, the resist is applied on the silicon substrate and the bitpattern is drawn into the RAM bit portions of a medium by electron beamdrawing. At this time, a bit pattern is not drawn into the portionequivalent to the ROM bits of the authentication region.

[0169] RIE processing is performed to this silicon substrate, andoriginal recording medium 102 is formed. In the surface of originalrecording 102, convex parts 102P are provided in the portionscorresponding to RAM bits, and flatness parts 102F are provided in theportion corresponding to ROM bits. And as shown in FIG. 12A, nickelelectroforming processing is performed to this original recording 102,and the stamper 104 is formed.

[0170] The stamper 104 has recesses 104D corresponding to RAM bits.Moreover, flatness parts 104F are formed in the portion corresponding toROM bits.

[0171] Next, as shown in FIG. 12B, the pattern of the stamper 104 istransferred. That is, the magnetic layer 116, which consists of a Pdbase layer 108 with a thickness of about 30 nm and vertical magneticrecording material CoCrPt with a thickness of about 50 nm, is formed asfilms on a glass substrate 106.

[0172] Furthermore, the resist film 112 with a thickness of about 50 nmis formed as a film on the magnetic layer 116. The stamper 104 is forcedon this surface, the resist film 112 is processed with nano-imprintinglithography, and the dot pattern whose portion corresponding to RAM bitsacts as convex parts 112P is transferred.

[0173] Next, as shown in FIG. 12C, the resist pattern 112 and themagnetic layer 116 are etched by Ar ion milling, and the magnetic bodydots 24 which consist of CoCrPt are formed. Next, as shown in FIG. 12D,a matrix 110 is formed between the magnetic dots 24, and the planarizingof the surface is carried out. That is, a matrix 110 is formed byforming SiO2 film with a thickness of about 50 nm as a film on the wholesurface, and embedding between the magnetic body dots 24. And thesurface of SiO2 film is ground by CMP (chemical mechanical polishing),and carried out the planarizing. Then, diamond-like carbon (DLC) isformed as a film on the whole surface as the protective film 114.

[0174] As shown in FIG. 13, when this substrate surface is observedusing MFM (Magnetic Force Microscope), the record region 30 and theauthentication region 20 are observed. In the record region 30, the RAMbits 24 are regularly located in a line in the matrix 110. In theauthentication region 20, the matrix region 110 and the RAM bits 24,which can be written in magnetically is observed.

[0175] Moreover, in the authentication region 20, the dots of the RAMbits 24 did not exist in the portions corresponding to the ROM bits inwhich it can not be written, but being covered with the matrix 110 isobserved.

[0176] Next, the recording-medium management system as magnetic recordplayback equipment which reproduces the recording medium of this exampleis explained, referring to FIGS. 14 and 15.

[0177]FIG. 14 is a sectional view showing the recording medium and thehead slider of magnetic record playback equipment of this example.

[0178] A recording medium has the recording layer and the protectionlayer 114 by which the record track belt in which the magnetic body dots24 carried out rule arrangement is formed on the glass substrate 106.The information corresponding to the address number and sector number ofeach record track belt is beforehand written in the magnetic layer whichforms the median strip.

[0179] The read-out head 71 and the write-in head 72 are carried at thetip of the head slider 70. The head slider 70 is positioned by thetwo-step actuator (not shown).

[0180]FIG. 15 is an outline figure showing the plane structure of thehead slider 70. About the size of the GMR read-out head 71 and thesingle magnetic pole write-in head 72, for example, length is about 30nm, and width is about 20 nm.

[0181] As mentioned above, by the same technique as the second examplementioned above about the recording medium of this example usingmagnetic record playback equipment which was explained, when theoverwrite erase pattern “01010101” is used, “key A” and “key B” areacquired. Moreover, by the RAM magnetic medium formed by copying thisrecording medium as it is, it has checked that it could not reproduce.

THE SEVENTH EXAMPLE

[0182] Next, as the seventh example of a the invention, a recordingmedium where the phase change RAM bits in which optical record ispossible are provided inside the inner circumference of the recordingtrack of the usual CD-R (Compact Disc-Recordable) by the opticallithography method, as the authentication region 20 will be explained.

[0183]FIG. 16 is a schematic diagram showing the recording medium ofthis example.

[0184] Firstly, the resist is applied to the region of an innercircumference only 1 mm from the data storing region 30 of the writeonce disc which has the same structure as commercialized CD-R.

[0185] Then, the holes of dots were formed with the bit pattern that thesignal for acquiring the key of the invention by the optical lithographymethod to this resist film is acquired was created.

[0186] Next, phase change material In—Sb—Te is laminated to this regionby the sputtering method, and the above-mentioned holes are embeddedwith the phase change material.

[0187] Finally, as a result of removing the whole resist film by thelift-off method, all materials other than RAM bits 24 which consist ofphase change material In—Sb—Te laminated in the hole are removed, andthe authentication region 20 is obtained by the inner circumference of aCD-R disc.

[0188] The bit data of the same “the key A” as the first example or thefifth example mentioned above are recorded on the authentication region20 obtained in such a way by an optical head.

[0189] Moreover, the moving image file data encrypted by encryptionprocessing using the “key A” formed previously and the “key B” set upseparately is recorded on the recording region of this CD-R.

[0190] Heretofore, the embodiments of the present invention have beenexplained, referring to the examples. However, the present invention isnot limited to these specific examples.

[0191] For example, the form of the recording medium of the invention isnot limited in the shape of a disc which was expressed in FIG. 1A orFIG. 6, but also includes various kinds of forms, such as the shape of acard, the shape of a tape, and the shape of a film.

[0192]FIG. 17 is a schematic diagram which illustrates a card-likerecording medium. That is, in recording-medium 10D shown in FIG. 17, theauthentication region 20 and the data storing region 30 are provided onthe surface of the card which consists of an organic material etc.

[0193] In the authentication region 20, the RAM bits and the ROM bitsare put together appropriately. Moreover, in the data storing region 30,data is recorded by RAM or a ROM system. About the record reproductionsystem, various kinds of systems including magnetic, optical and anoptical magnetism system can also be used.

[0194]FIG. 18 is a schematic diagram showing the recording-mediummanagement system which manages the recording medium of the shape ofsuch a card. That is, the head 200 which can appropriately performreading and the writing of data in the authentication region 20 and thedata storing region 30 of a recording medium 10 is also provided in thiscase.

[0195] This head 200 is controlled by the control part 300, and canperform authentication processing which consists of a series of stepswhich were mentioned above about FIG. 2.

[0196]FIG. 19 is a schematic diagram showing the recording medium, whichused semiconductor memory and a magnetic material memory.

[0197] That is, recording-medium 10E is a semiconductor memory equipmentformed using semiconductors, such as silicon (Si) and gallium arsenide(GaAs), or magnetic memory equipment using magnetic effects, such as GMR(giant magnetoresistance effect) and TMR (tunneling magnetoresistanceeffect), and provides the authentication region 20 and the data storingregion 30 are provided.

[0198] In the authentication region 20, the RAM bit which consists of aRAM type memory element, and the ROM bit which consists of a ROM typememory element are put together appropriately.

[0199] Moreover, in the data storing region 30, a RAM type memoryelement or a ROM type memory element is accumulated, and data isrecorded by the RAM system or the ROM system.

[0200] As RAM type semiconductor memory element or magnetic memoryelement, DRAM (Dynamic Random Access Memory), FRAM (Ferroelectric RandomAccess Memory), MRAM (Magnetic Random Access Memory), E²PROM(Electrically Erasable Programmable ROM), etc. can be used.

[0201] As a ROM type semiconductor memory element, SRAM (Static RandomAccess Memory) and a mask ROM, etc. can be used. It is possible toaccumulate and form these semiconductor memory elements on asemiconductor substrate, to read out sequentially the informationmemorized by each memory element like the above-mentioned embodiment,and to perform authentication etc.

[0202]FIG. 20 is a schematic diagram showing the recording-mediummanagement system which manages the recording medium which expressed inFIG. 19. That is, this management system has read-out and the write-inpart 200 connected removable to recording medium 10 by the connectoretc., and the control part 300 which controls this.

[0203] Read-out and the write-in part 200 have for example, theselection means for choosing either of the memory elements arranged inthe shape of a matrix, the sense amplifier and the source of bias forreading (reproduction), and a voltage (current) impression means forwriting in (record).

[0204] In record reproduction of recording-medium 10E, the data of theRAM bit and a ROM bit provided in the authentication region 20 is readout sequentially like the above-mentioned embodiment, “key A” isacquired, and the overwrite erase of the authentication region 20 iscarried out with predetermined data to after an appropriate time.

[0205] Then, “key B” is acquired by scanning the authentication region20.

[0206] And the control part 300 can manage propriety of access to ordecryption of the data storing region 30, being based on these “key A”and “key B.”

[0207] While the present invention has been disclosed in terms of theembodiment in order to facilitate better understanding thereof, itshould be appreciated that the invention can be embodied in various wayswithout departing from the principle of the invention. Therefore, theinvention should be understood to include all possible embodiments andmodification to the shown embodiments which can be embodied withoutdeparting from the principle of the invention as set forth in theappended claims.

What is claimed is:
 1. A recording medium comprising: an authenticationregion having a RAM bit and a ROM bit, the RAM bit being over-writableof data at least once by a first writing condition, and the ROM bitbeing not over-writable of data by the first condition; and a datastoring region.
 2. The recording medium according to claim 1, furthercomprising a non-recording region enclosing the RAM bit and the ROM bit,and the non-recording region being not over-writable by the firstwriting condition.
 3. A recording-medium management method comprising:obtaining a first data line from an authentication region of a recordingmedium, the authentication region including a first data pattern of aRAM bit and a ROM bit, the first data line being corresponding to thefirst data pattern, the RAM bit being over-writable of data at leastonce by a first writing condition, and the ROM bit being notover-writable of data by the first writing condition; overwriting apredetermined data to the RAM bit; obtaining a second data line from therecording medium, the second data line being corresponding to a seconddata pattern of the over-written RAM bit and the ROM bit, and decryptingan encrypted data stored in a data storing region of the recordingmedium in reference to the first and second data lines.
 4. Arecording-medium management method comprising: obtaining a first dataline from an authentication region of a recording medium, theauthentication region including a first data pattern of a RAM bit and aROM bit, the first data line being corresponding to the first datapattern, the RAM bit being over-writable of data at least once by afirst writing condition, and the ROM bit being not over-writable of databy the first writing condition; overwriting a predetermined data to theRAM bit; obtaining a second data line from the recording medium, thesecond data line being corresponding to a second data pattern of theover-written RAM bit and the ROM bit, and judging propriety of an accessto a data storing region of the recording-medium in reference to thefirst and second data lines.
 5. A recording-medium management systemcomprising: a reproduction part; a recording part; and a control partperforming a first control to obtain a first data line from anauthentication region of a recording medium by making the reproductionpart read the authentication region, the authentication region-includinga first data pattern of a RAM bit and a ROM bit, the first data linebeing corresponding to the first data pattern, the RAM bit beingover-writable of data at least once by a first writing condition, andthe ROM bit being not over-writable of data by the first writingcondition; a second control to make the recording part overwritepredetermined data to the RAM bit; a third control to obtain a seconddata line from the recording-medium by making the reproduction part readthe authentication region, the second data line being corresponding to asecond data pattern of the over-written RAM bit and the ROM bit, and afourth control to perform an authentication with regard to the recordingmedium in reference to the first and second data lines.
 6. Therecording-medium management system according to claim 5, wherein theauthentication is a decryption procedure of an encrypted data stored inthe recording medium.
 7. The recording-medium management systemaccording to claim 5, wherein the authentication is a judgment ofpropriety of an access to a data stored in the recording medium.
 8. Therecording-medium management system according to claim 5, wherein thepredetermined data consist of only either one of binary values.
 9. Therecording-medium management system according to claim 5, wherein thepredetermined data has a sequence in which one of binary values andanother of binary values appear by turns.
 10. The recording-mediummanagement system according to claim 5, wherein the recording medium hasa plurality of the authentication regions, and the control part performsthe first through fourth control in correspond to each of theauthentication regions.
 11. The recording-medium management systemaccording to claim 10, further comprising a memory to store at least oneof the obtained first and second data lines, the control part performinga fifth control to erase at least one of the first and second data linesstored in the memory.
 12. The recording-medium management systemaccording to claim 11, wherein the control part performs the fifthcontrol when reading data region of the recording medium correspondingto the data to be erased is performed by a predetermined times.
 13. Therecording-medium management system according to claim 11, wherein thecontrol part performs the fifth control when the recording medium isremoved from the recording-medium management system.
 14. Therecording-medium management system according to claim 11, wherein thecontrol part performs the fifth control when a predetermined time passedafter the first or second data line is obtained.
 15. Therecording-medium management system according to claim 11, wherein thecontrol part performs the fifth control when a use of the recordingmedium is finished.
 16. The recording-medium management system accordingto claim 5, further comprising a memory to store at least one of theobtained first and second data lines, the control part performing afifth control to erase at least one of the first and second data linesstored in the memory.
 17. The recording-medium management systemaccording to claim 16, wherein the control part performs the fifthcontrol when reading data region of the recording medium correspondingto the data to be erased is performed by a predetermined times.
 18. Therecording-medium management system according to claim 16, wherein thecontrol part performs the fifth control when the recording medium isremoved from the recording-medium management system.
 19. Therecording-medium management system according to claim 16, wherein thecontrol part performs the fifth control when a predetermined time passedafter the first or second data line is obtained.
 20. Therecording-medium management system according to claim 16, wherein thecontrol part performs the fifth control when a use of the recordingmedium is finished.
 21. The recording-medium management system accordingto claim 5, wherein the control part performs a sixth control to makethe recording part overwrite data to the RAM bit in order that the firstdata line is obtained when the first control is performed to therecording medium.